Back to all

The Tuffy Tire & Auto Service Center Lockport Guide to Tire Specs

August 26, 2018

You know you need new tires, but you're not sure what type. You look at a tire to get the size: 225, 50, R, 16, 92, H. All the way to the Lockport service center you keep repeating it over and over. You even say it over in your mind while waiting in line. Then you get to the counter and the manager asks what size you need. Then your mind goes blank.

Tire size can be confusing for many Lockport drivers. There's so much on the side of the tire, and it's hard to keep straight.

Even though there's a lot on a tire - if you know what it all means, it's actually more helpful than confusing for Lockport tire shoppers. Let's start with the size number.

For example, let's say a tire reads: 225 50 R 16 92 H. The 225 part is the width of the tire in millimeters - the width between the sidewalls of an inflated tire with no load. The 50 is the aspect ratio - the ratio of the sidewall height to the tread width. Off-road tires will have a higher number and high performance tires will have a lower number.

The R signifies it's a radial tire. And 16 is the rim or wheel size in inches.

The 92 is the load rating index - it's the load carrying capacity of a tire. The higher the number, the more it can safely carry. Your empty vehicle can be safe with a lower number, but you'll need a higher rating if you routinely haul heavy loads around Lockport. The next letter is the speed rating. Not all tires sold in Lockport are speed rated. The ratings generally follow the alphabet: the further up the alphabet, the higher the speed rating - with the exception of H - it comes between U and V (don't ask why).

There's a lot of fine print that most Lockport area drivers probably need a magnifying glass to read. But there are a couple of other large print items of interest. One is the tread type: highway, mud and snow, all season, severe snow, etc.

And then there are the Uniform Tire Quality Grading System markings. The first is a tread wear index. 100 is the base line - a lower number is poorer and a higher number is better. All things being equal, a tire rated 200 would wear twice as long, on a government test track, than one rated at 100. These wear grades are only valid within the manufacturers product line - you can't compare with others. And it's important to note that a lower rating might be just what you want - a high performance, sticky tire has a softer rubber compound and won't wear as long, but boy, will it take those corners on twisting Illinois roads.

The next is a traction grade. This measures the tire's ability to stop on wet pavement in government tests. A - the best, B - intermediate, C - acceptable.

Temperature grade measures a tire's resistance to heat buildup in government tests. A, B and C - from best to acceptable.

It's safe for Lockport drivers to go with the vehicle manufacturers original equipment recommendations that came on your car. But if you want to make adjustments, you'll now be better equipped to communicate with your friendly and knowledgeable Tuffy Tire & Auto Service Center Lockport tire professional.

Tuffy Tire & Auto Service Center Lockport
600 E 9th Street
Lockport, Illinois 60441
815-838-3700

 

More articles from Tuffy Lockport

The Little Valve that Could (PCV Valve Replacement)

August 3, 2025

It's easy to get letters like PVC and PCV mixed up. PVC is a plastic that's used in a lot of things, especially plumbing pipes. And PCV is a valve that helps your engine burn off excess fumes rather than having them pollute our atmosphere. PCV stands for positive crankcase ventilation. When y... More

Your Vehicle's Other Power Plant (Alternator Replacement)

July 27, 2025

Your vehicle's engine is probably the first thing that comes to mind when you think of a power plant. But it has another power source that is vital as well: the alternator. The alternator is what puts out the electricity that powers such things as your lights, power windows, sound system, and na... More

Out of Joint (CV Joint and Boot Replacement)

July 20, 2025

If you have a front-wheel-drive vehicle, it has components called CV joints which enable you to turn your wheels smoothly. The CV stands for constant velocity. In essence, its a set of gears that connect a shaft that allows power from the transmission to be sent to the wheels. When you turn the ... More